Critical Resistance at the Superconductor-Insulator Transition in Hole-Doped Cuprates

Here, we show that in several p-type cuprates, the superconductor-to-insulator transition (SIT) occurs at the critical sheet resistance approximately equal to the quantum resistance of pairs, RQ=h/4$e^{2}$=6.5 kΩ. In a relatively broad range of temperatures and doping levels near the quantum critical point, the sheet resistance shows universal behavior and scaling characteristic of two-dimensional quantum phase transition.